Update fairness.rst.txt

Author: ZebinYang

docs/_build/html/_sources/guides/testing/fairness.rst.txt

@@ -27,7 +27,7 @@ PIML supports various fairness metrics, as shown below. In specific, we use the
 .. math::
 
    \begin{align}     
-   Precision Ratio = \frac{(TP_{p}) / (TP_{p}+FP_{p})}{(TP_{r}) / (TP_{r}+FN_{r})}.
+   Precision Ratio = \frac{(TP_{p}) / (TP_{p}+FP_{p})}{(TP_{r}) / (TP_{r}+FP_{r})}.
    \end{align}
 
 - **Recall**: True positive rate disparity ratio.